The principal objective of the Radiopharmacy and Assays Core (Core B) is to support Project 1: Radioimmunotherapy: Clinical Studies, Project 2: Pretargeting with anti-CEA Antibodies for Therapy, and Project 3: CEA Targeted Immunotherapeutics by providing expertise and facilities to prepare radiolabeled antibodies and quality control for therapeutic and imaging reagents. Yttrium-90 radiolabeled chimeric/humanized T84.66 anti-CEA antibody will be used in the clinical trials for colon and lung cancer satients, and yttrium-90 radiolabeled Herceptin will be used in breast cancer patients at the City of Hope National Medical Center, lndium-111 radiolabeled chimeric/humanized T84.66 antibody, Avastin and Herceptin will be used for imaging and dosimetry studies. The radiopharmacy will support Project 1 by providing the radiolabeled antibodies and will provide quality control for these reagents. This Core is also responsible for the analysis of patient (and animal) blood samples to evaluate the blood clearance and stability of the administered products. Patient sera samples are also analyzed to monitor the patient's immune response to the injected antibody constructs. Core B also performs the radiolabeling of all the antibodies, engineered antibodies, chemically modified antibodies and haptens for preclinical in vitro and in vivo use. Procedures involved in preparation of the radiopharmaceutical agents include chelate conjugate chemistry and conjugation as well as the antibody radiolabeling. As part of its core activity the Radiopharmacy also develops the monoclonal antibody construct conjugation methodologies for the clinical grade materials to be prepared in the cGMP facility for the Phase I trials. Core B will be associated with all three Projects as well as Cores A, C, D and E in this application.